Robotic partial nephrectomy for hilar renal masses

Abstract

Introduction and objectives: Centrally located renal tumours pose significant challenges for partial nephrectomy. We describe our technique for robotic-assisted partial nephrectomy (RAPN) for hilar tumour resection and report our outcomes, comparing hilar vs non-hilar tumours. Methods: Our single surgeon series consists of 302 cases, including 22 hilar masses. Steps for resection are described. Keys to a successful outcome include careful pre-planning, meticulous hilar dissection, and close tumour resection to avoid injuring uninvolved sinus structures. Resection then leaves a unique defect precluding closure in the usual manner. We propose three layers; individual ligation of larger vessels, continuous suture of the corticomedullary junction, then use of adjunct haemostatic agents such as SURGICEL® bolsters for cortical compression. Results: The median age of patients with hilar and non-hilar tumours were similar (59 years vs 60.5 years). Hilar tumours were significantly smaller (28.3 ± 7.2 mm vs 34.8 ± 16.0 mm, p = 0.03) and had higher median nephrometry scores (8 vs 7, p = 0.01). Peri-operative outcomes were similar between the 2 groups for operative duration (133.2 ± 33.2mins vs 129.5 ± 33.8mins, p = 0.31) with a trend towards less blood loss (115.5 ± 185.6cc vs 122.5 ± 158.1cc, p = 0.42) and longer warm ischaemia time (22.3 ± 9.9mins vs 18.6 ± 6.5mins, p = 0.01) for hilar tumours. Median length of stay was similar at 3 days (hilar IQR 2–3.5 days, non-hilar IQR 2–4 days). No cases converted to open or radical nephrectomy. Malignant tumours were more common for non-hilar group (86.3% vs 63.6%, p = 0.01), while benign histology was significantly more common in hilar masses (OR 3.6, p<0.01). There was only one positive margin in the hilar group. There were no major Clavien-Dindo complications for the hilar group and no recurrence at a mean follow-up of 33.0months (s = 22.1). Glomerular filtration rate 6 months post-operation was better preserved for patients with hilar masses (75% vs 67%, p = 0.33). Conclusions: Hilar renal masses are complex but with proper steps, a safe and successful RAPN is possible.

Keywords

• Robotic partial nephrectomy
• Renal tumours
• Renal hilar masses
• Minimally invasive
• Surgery